This application claims the priority of German Application No. 103 10 179.9-13 filed Mar. 8, 2003, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an oil catching system for an internal-combustion engine, particularly for an opposed-cylinder engine. Certain preferred embodiments of the invention relate to an oil catching system for an internal-combustion engine, particularly for an opposed-cylinder engine, having an oil catching housing arranged below a crankcase, in which oil catching housing an oil suction space is provided from which lubricating oil is transported to consuming devices by way of a main oil pump equipped with an oil suction pipe, and wherein at least one oil collecting space adjoins the oil suction space, in which oil collecting space the lubricating oil coming from the consuming devices is returned by way of an oil pipe, the oil suction space being separated from the oil collecting space by at least one oil separating wall in which at least one passage opening is arranged which can be controlled by way of a flap, by way of which passage opening the lubricating oil can flow from the oil collecting space into the oil suction space.
In the case of the current water-cooled 6-cylinder horizontally opposed engines of the 911 Carrera Series (Dr. Ing. h.c. F. Porsche Corporation), an oil separating case, which is fastened at the oil pan cover is provided in the oil bearing housing or in the oil pan, in which oil separating case the oil sump for the lubricating oil supply of the engine is constructed. The lubricating oil returned from the consuming devices into the oil pan is first guided back outside the oil separating case forming the oil suction space, before it flows by way of openings monitored by flaps in the oil separating case into the actual oil suction space.
It is an object of the invention to further improve the so-called integrated dry sump with respect to its functionality in order to reach a high degree of integration which simultaneously includes a reduction of the extent of the preassembly.
According to certain preferred embodiments of the invention, this object is achieved by providing an oil catching system for an internal-combustion engine, particularly for an opposed-cylinder engine, having an oil catching housing arranged below a crankcase, in which oil catching housing an oil suction space is provided from which lubricating oil is transported to consuming devices by way of a main oil pump equipped with an oil suction pipe, wherein at least one oil collecting space adjoins the oil suction space, in which oil collecting space the lubricating oil coming from the consuming devices is returned by way of an oil pipe, the oil suction space being separated from the oil collecting space by at least one oil separating wall in which at least one passage opening is arranged which can be controlled by way of a flap, by way of which passage opening the lubricating oil can flow from the oil collecting space into the oil suction space, and wherein a wall section is provided which bounds the oil collecting space and is spaced away from the oil separating wall, which wall section, relative to the passage opening in the oil separating wall, extends in a diagonally inclined manner and is used as a flow-off surface for the lubricating oil returned into the oil collecting space.
According to preferred embodiments of the invention, a bevel is provided which is shaped out of a wall section in the oil collection space and which is used as the flow-off surface for the lubricating oil returned into the oil collecting space. This obliquely extending side wall of the oil collecting space advantageously assists the oil return from the cylinder heads to the suction point. The lubricating oil, which is, for example, returned from the cylinder heads, flows onto the obliquely extending flow-off surface and from there by way of the openings provided in the oil separating wall into the oil suction space. Because of the construction of obliquely extending flow-off surfaces, the volume of the oil collecting space can be reduced while the functionality of the pressure lubrication is maintained. Simultaneously, as a result of the approach flow of the returning oil, which is directed in a defined manner, the flow-off surfaces are used for defoaming the lubricating oil. They therefore take over the function of the otherwise normally used oil/air separators, the so-called swirl pots.
Additional advantages and advantageous further developments of the invention are described herein and in the claims.
According to certain preferred embodiments of the invention, the wall section, which in the oil collecting space is equipped with the lubricating oil flow-off surface, is advantageously shaped in one piece out of an oil cover closing off the oil catching housing in the downward direction. In certain preferred embodiments the cover is made using plastic and in this case, the plastic part provided for the flow-off surface can be shaped out such that previous dead spaces existing in the oil sump can be considerably reduced. Thus, the internal-combustion engine can be operated by means of a lower lubricating-oil circulating quantity, whereby weight and cost advantages can be achieved.
According to certain preferred embodiments of the invention, the obliquely extending flow-off surfaces, which are simultaneously provided for the defoaming of the lubricating oil, may additionally be provided with ribs, naps or similar shaped bodies so that the lubricating oil is correspondingly deaerated on the way into the oil suction space.
According to certain preferred embodiments of the invention, the two oil separating walls bounding the oil suction space as well as oil return flow pipes arranged in the oil collecting space are combined in one piece as a sort of preassembly module. The integration of the components belonging to the dry sump is further increased if the oil suction snorkel arranged in the oil collecting space is combined with the two oil return flow pipes in one piece as a joint module.
Two embodiments of the invention will be explained in detail in the following description and drawing.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.